[Gimp-developer] Please help me with dependency details to build GIMP 2.10 on CentOS 7

["Deft Developer" <dev hymes name>]

My org has CentOS 7, and I REALLY want to build GIMP 2.10. CentOS is
conservative, and does not ship with many of 2.10's dependencies. My problem
is that after I "have" 2.10's dependencies, I don't know how to configure
autoconf and configure to find them. I have read
https://wiki.gimp.org/wiki/Hacking:Building,
https://wiki.gimp.org/wiki/Hacking:Developer_FAQ#Compiling_GIMP
,https://www.gimp.org/source/#gimp-requirements 

 and lots of other pages that I have googled. But they are missing the
details on setting  env variables and command-line options. I have all the
tarballs listed in the pages above, and I have built most of the packages.
But some packages ( gegl, fontconfig ) won't build because they can't find
THEIR dependencies, though they, too, have been built, or installed via yum.

Here is what I have bash source before I run "autogen.sh
--prefix=$INSTALL_PREFIX" or "configure --prefix=$INSTALL_PREFIX" for each
dependency:

source /usr/bin/scl_source enable devtoolset-7

 

export GIMP_BLD_HOME=$HOME/projects/3rdparty/gimp_world/gimp

export SRC_DIR=$GIMP_BLD_HOME/src

export INSTALL_PREFIX=$HOME/opt/gimp-10

export LD_LIBRARY_PATH=$INSTALL_PREFIX/lib:/usr/local/lib:$LD_LIBRARY_PATH

export PKG_CONFIG_PATH=$INSTALL_PREFIX/lib/pkgconfig:$PKG_CONFIG_PATH

export PATH=$INSTALL_PREFIX/bin:$PATH

export CFLAGS="-march=native -O3"

 

All the above dirs  exist. 

With  gexiv2, I run "./configure" - - - "sudo make install" without error,
but GIMP 2.10 autogen still fails with: 

Error: missing dependency gexiv2 >= 0.10.6 .

 

~/opt/gimp-10/libs has new libgexiv* files there,.

I cannot gegl to build, it fails to find glib-dev 2.54 installed by yum ,
nor  can I build fontconfig, because it fails to find freetype > 21, though
I have built and "installed" fretype version 26.

Sorry, I'm not at all a C++ guy! Please be explicit, and I thank you very,
very much!